How do I properly integrate KuKoin API w/ secret, passphrase, and key signature using Google Apps Script?

Over the past few days I've been trying to engineer a piece of code that can help me access this api https://api-futures.kucoin.com and this endpoint /api/v1/transaction-history?offset=1&forward=true&maxCount=50 using hash encryption.

Reference document https://docs.kucoin.com/futures/#authentication . I've been looking at the reference document, then I have written a script that should work but is not and I just need some guidance.

function KuCoinRequest(){
    // GET /api/v1/transaction-history?offset=1&forward=true&maxCount=50
    var key ='xx'
    var secret = 'xx'
    var passphrase = 'xx' 
    var url = "https://api-futures.kucoin.com"; //endpoint
    var timestamp = '' + Number(new Date().getTime()).toFixed(0);
    var command = "GET";
    var endpoint = "/api/v1/transaction-history?offset=1&forward=true&maxCount=50"
    var str_to_sign = timestamp + command + endpoint;
    // var signature = Utilities.computeHmacSha256(str_to_sign, secret);
    // var encodedPass = Utilities.computeHmacSha256(passphrase, secret);
    var signature = Utilities.computeHmacSignature(Utilities.MacAlgorithm.HMAC_SHA_256, str_to_sign, secret)
    var encodedPass = Utilities.computeHmacSignature(Utilities.MacAlgorithm.HMAC_SHA_256, passphrase, secret);
    var params = {
        'method': "GET",
        'headers' : {
            'KC-API-SIGN': Utilities.base64Encode(signature),
            'KC-API-KEY': key,
            'KC-API-TIMESTAMP': timestamp,         
            'KC-API-PASSPHRASE': Utilities.base64Encode(encodedPass),     
            'KC-API-KEY-VERSION': '2',     
            'muteHttpExceptions': true       
        }
    };         
    query = url + endpoint;      
    var data = UrlFetchApp.fetch(query, params);
    Logger.log(data.getContentText());   
    // printJsonKucoin(data, endpoint); 
    return data;
}